<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title><block name="title">TITLE</block></title>
</head>
<body>
<block name="body"></block>
<block name="test">
    默认内容，没有定义就不会覆盖我
</block>
<include file="footer" />
</body>
</html>